The majority of the baryons in the present-day universe are missing in thatthey are not in galaxies or as cool intergalactic gas. These baryons are mostlikely diffuse gas at 1E5 - 1E7 K in regions of modest overdensity, and thesuperposition of many such regions produces X-ray emission that accounts forabout 5-20% of the X-ray background in the 0.2-1 keV range. To detect thisemission, we propose to use the shadowing properties of the extended gas in theedge-on galaxy NGC 4244. This gas will absorb some of the background emission,leading to a local minimum in the soft X-ray background (a shadow).
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2008-11-16T19:34:56Z/2008-11-19T10:10:13Z
Version
17.56_20190403_1200
Mission Description
The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.
European Space Agency, Prof JOEL BREGMAN, 2009, 'Detecting Emission from the Missing Baryons Through X-Ray Shadowing', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-zkjtsus
